In This Edition

Joint and Muscle Problems for Overweight Youth

Children
and adolescents who are overweight are more likely than their normal weight counterparts
to suffer bone fractures and have joint and muscle pains, according to a new
study from NIH's National Institute of Child Health and Human Development. Overweight
youth in the study were also more likely than non-overweight youth to develop
changes in the knee joint that make movement more difficult.

A total of 355 Washington, D.C. area children and adolescents took part in the
study. Of these, 227 were classified as overweight and 128 as non-overweight.
The children underwent a detailed physical examination and were questioned about
whether they had experienced any joint, bone or muscle-related problems. They
also provided answers to a questionnaire designed to gauge the impact their weight
had on their quality of life, ranking on a 5-point scale whether statements about
impaired mobility applied to them. The statements included: “I have trouble using
stairs,” “I feel clumsy or awkward,” and “I have trouble getting up from chairs.” In
addition, the researchers used a technique called Dual Energy X-Ray Absorptiometry
(DXA) to detect any effects of being overweight on the feet, ankles and knees.

The results were published in the June 2006 issue of Pediatrics. The
researchers found that the overweight youth were more likely to experience bone
fractures and muscle and joint pain than those who weren’t overweight. The most
common joint complaint was knee pain, with 21.4% of overweight youth reporting
knee pain, compared to 16.7% of non-overweight youth. The overweight youth were
more likely to report impaired mobility as well. DXA scans showed that overweight
youth were also more likely to experience changes in how the bones of the thigh
and leg meet at their knees.

The researchers noted that, while overweight children and adults have a greater
bone density than their non-overweight counterparts, this greater density didn’t
protect the youth in the study from bone fractures. This may be because someone
who’s overweight can fall with greater force than someone who isn’t. Other studies
have suggested that overweight boys also have poorer balance than non-overweight
boys, and so are more likely to fall.

“Bone, muscle and joint problems are particularly troubling in this age group,” NIH
Director Dr. Elias A. Zerhouni said. “If overweight youth fail to attain normal
weight, they will likely experience an even greater incidence of these problems
when they reach later life.” NIH has developed a variety of on-line materials
to help young people make healthy choices about diet and exercise.